(1173) Impact of Comprehensive Medication Review on Oral Antidiabetic Drugs Adherence in Type II Diabetic Medicare Beneficiaries

Objectives: Nonadherence to oral antidiabetic (OAD) medications has been shown to result in poor glycemic control, increased morbidity, excess mortality, and higher health care spending for the approximately 37.7 million people with diabetes. Given this burden, diabetes is one of 9 chronic health conditions prioritized as a core chronic condition in the Medicare medication therapy management (MTM) program and OAD adherence is heavily weighted measure in the Medicare Star Ratings program. Although a number of studies have examined the effectiveness of MTM, these studies have resulted in conflicting results signaling the need for additional research. Our study was conducted to ascertain whether the implementation of Comprehensive Medication Reviews (CMRs) - a service that offers qualified Medicare enrollees real-time, interactive medication assessments conducted by healthcare professionals - could yield significant improvements in type 2 diabetes mellitus (T2DM) treatment quality, particularly in terms of medication adherence and the utilization of statins.

Methods: A retrospective observational study using a difference-in-difference (DID) approach was conducted on Medicare beneficiaries with validated T2DM eligible for CMR from 2013-2019. To be included in the study, patients needed to have a minimum of two OAD prescriptions documented within the one-year baseline period. Beneficiaries lacking continuous enrollment in Medicare Part A/B/D were excluded from the analysis. The primary objective of this investigation was to compare the Proportion of Days Covered (PDC) by OAD medications during the year before and after a predefined index date. This index date was established as the date when CMR services were first received for the exposure group and the date when CMR was offered for the treatment group. A one year washout was incorporated to capture new use of CMR with no prior exposure. PDC calculations were based on the dates of the first OAD prescription within the baseline and post-CMR periods. Additionally, changes in statin utilization rates were assessed between these two groups. To mitigate potential bias and balance covariates, the study employed the Inverse Probability Treatment Weight (IPTW) method.

Results: The study enrolled 78,706 patients in the CMR exposure group and 116,739 in the control group. Although both the treatment and control group experiences a decline in PDC in the post-period, the decline was significantly less pronounced in the CMR exposure group compared to the control group using IPTW (-10.3% vs -12.3%; DID, 2.0%, 95% CI, 1.7% to 2.2%). The proportion of CMR recipients considered adherent (PDC > 80%) to OAD decline from 76.3% to 67.6% following a CMR relative to the control group who experienced a decline from 74.1% to 63.6% over the same period. Logistic regression revealed that patients who received CMR were more likely to maintain a PDC over 0.8 compared to those in the control group (OR, 1.18, 95% CI, 1.15 to 1.20). Regarding statin use rate, it remained relatively stable, changing from 43.6% to 43.7% prior to and after CMR exposure respectively, while it decreased from 43.6% to 42.9% in the control group over the same period. In logistic regression models, the CMR exposure group was significantly more likely to have concurrent statin use relative to the control group (OR, 1.16, 95% CI, 1.13 to 1.19).

Conclusions: To our knowledge, this is the largest and most widely generalizable estimate of the effect of MTM on diabetes medication quality. We find that receipt of a CMR improved adherence to oral antidiabetic treatment and an increased the likelihood of using statins in this population. To further enrich our comprehension, future investigations should explore the potential benefits of CMR in different facets of health outcomes, such as hospitalization rates and medical expenses among T2DM patients.